Nuclear imaging, such as positron emission tomography (PET), generates imaging data based on receipt of annihilation photons at photo detectors during imaging. The photo-detectors include crystals each having an energy response (photopeak) to a received photon. In an ideal imaging device, the photopeak response of each crystal remains stable. However, in actual applications, the photopeak response of each crystal can vary from scan to scan and/or during the course of a scan, for example, due to count rate changes or environmental changes. Properly tuned scanners and data correction methods are required to obtain accurate quantitative images.
Current imaging systems utilize a set-up and calibration process that is performed prior to performing a plurality of scans. For example, in some instances, an imaging device is calibrated once per day. Because the photopeak locations of the detectors can vary, the imaging device can be less accurate during subsequent scans. It is not practical to perform current calibration processes prior to each scan (due to time constraints, training, etc.), and artifacts can be introduced due to photopeak variation in patient/phantom scans.